Fiber mat, fiber-reinforced resin material composed of fiber mat, and tubular lining material using fiber-reinforced resin material

Abstract

To provide: a fiber mat which constitutes a lining material that can be made to fit into a shape of an aging existing structure and improve strength of the aging existing structure; a fiber-reinforced resin material composed of the fiber mat, and a tubular lining material using the fiber-reinforced resin material.SOLUTION: A fiber mat 20 comprises: a first layer 24 that is formed by arranging a plurality of short reinforcing fibers 24a of a predetermined length that extends in the same direction and stacking the short reinforcing fibers in the length direction of the fibers so as to extend in the length direction of the fiber mat 20; and a second layer 26 that is laminated on the first layer 24, and is formed by stacking and arranging a plurality of short reinforcing fibers 26a of a predetermined length that extends in the same direction in the length direction in a laminated state so as to intersect with the short reinforcing fibers 24a of the first layer 24 at an angle of 45° to 90°.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a fiber mat, a fiber-reinforced resin material, and a tubular lining material, and in particular to a fiber mat constituting a lining material used to cover the inner surface of an existing structure when repairing the existing structure, a fiber-reinforced resin material composed of the fiber mat, and a tubular lining material using the fiber-reinforced resin material. [Background technology]

[0002] Existing pipes, such as sewer pipes, deteriorate over many years of use, and their useful life is generally considered to be about 50 years. In recent years, the number of sewer pipes that have exceeded their useful life has been increasing, and in aging sewer pipes, cracks in the pipes can allow groundwater and soil around the pipe to flow into the pipe, which can cause cavities in the ground and lead to ground subsidence. Sewer pipes are also susceptible to the effects of earthquakes and other ground movements, and for various other reasons, some kind of repair is required at certain times.

[0003] As a method for repairing deteriorated existing pipes, a method of covering the inner surface of an existing pipe with a hardened tubular lining material is known. For example, Patent Document 1 describes a method for repairing a sewer pipe using a tubular lining material formed by impregnating a fiber material such as glass fiber with a curable resin composition and forming the fiber material into a tubular shape. In this method, the tubular fiber reinforced resin material is introduced into the sewer pipe in an uncured state, and then compressed air is supplied to an enclosed space formed by blocking both ends of the tubular lining material, and the tubular lining material is pressed against the inner surface of the sewer pipe. In this state, the tubular lining material is hardened using heat or light, and the inside of the sewer pipe is covered with the hardened tubular lining material.

[0004] The tubular lining material used in this method is manufactured by impregnating a band-shaped fiber mat made of fibers such as glass fibers with a curable resin composition, and spirally winding this band-shaped fiber reinforced resin material around a cylinder to form a tubular body, as described in Patent Document 2. The manufactured tubular lining material is formed so that its outer diameter is slightly smaller than the inner diameter of the existing pipe to be repaired, and the diameter of the tubular lining material is expanded by introducing the compressed air as described above, so that the outer surface of the tubular lining material is in close contact with the inner surface of the existing pipe.

[0005] Since the inner surface of an aged existing pipe is uneven and non-uniform, if the expansion rate of the tubular lining material is small, the adhesion of the lining material is low. In Patent Document 2, the length of the fibers constituting the fiber mat in the tubular lining material is set to 2 cm to 20 cm, and further, the extension direction of the fibers is aligned in one direction, so that when the tubular lining material is expanded in diameter by compressed air, the fibers are easily separated from each other, increasing the expansion rate of the tubular lining material and improving adhesion to the existing pipe. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Patent No. 3691881 [Patent Document 2] Patent No. 3675476 Summary of the Invention [Problem to be solved by the invention]

[0007] However, in the tubular lining material described in Patent Document 2, since the fiber length is short, there is a problem that the strength of the fiber in the longitudinal direction is somewhat lower than that of a tubular lining material made of long fibers.

[0008] The present invention has been made in consideration of the above-mentioned problems, and its object is to provide a fiber mat that constitutes a lining material that can be made to fit the shape of an existing deteriorated structure and that can improve its strength, a fiber reinforced resin material made from the fiber mat, and a tubular lining material that uses the fiber reinforced resin material. [Means for solving the problem]

[0009] In order to achieve the above object, the fiber mat according to claim 1 is A first layer is formed by arranging a plurality of short reinforcing fibers of a predetermined length extending in the same direction as the fiber mat so as to extend long in the length direction of the fiber mat while overlapping the fibers in the length direction; and a second layer which is laminated on the first layer and which is formed by overlapping and arranging a plurality of short reinforcing fibers of a predetermined length extending in the same direction as the first layer so as to intersect with the short reinforcing fibers of the first layer at an angle of 45° to 90° in the laminated state.

[0010] According to this configuration, when a lining material is formed from the fiber mat, each reinforcing fiber constituting the second layer of the fiber mat overlaps with the multiple short reinforcing fibers constituting the first layer in the thickness direction of the fiber reinforced resin material in a direction intersecting at an angle of 45° to 90°. As a result, each reinforcing fiber constituting the second layer plays the role of a joint material for the multiple short reinforcing fibers in the first layer, improving the adhesion between the short reinforcing fibers in the first layer in the lining material. As a result, when the lining material is used as a base material for a lining material used to repair an existing structure, the strength in the extension direction of the short reinforcing fibers in the first layer can be improved. In addition, since the fibers in the first and second layers of the fiber mat are short reinforcing fibers that are aligned in one direction, when a lining material in which the fiber mat is impregnated with a curable resin composition is pressed against an existing structure and cured, the fibers in the first and second layers are in a state where they are easily separated from each other in their extension direction, and therefore, they are easily bent and can be well fitted to the surface shape of the existing structure.

[0011] The invention described in claim 2 is the fiber mat described in claim 1, The composite material is characterized in that it includes a third layer between the first layer and the second layer, the third layer being composed of fibers with irregular fiber orientation.

[0012] According to this configuration, by disposing the third layer, which has irregular fiber orientation, between the first and second layers, whose fibers extend in the intersecting direction, the fibers are easily entangled between the layers, improving the adhesive strength between the layers. Also, because the third layer has irregular fiber orientation, the fibers are easily separated when the lining material is made of a fiber mat and the curable resin composition is cured, allowing the lining material to fit well to the surface shape of the existing structure.

[0013] The invention described in claim 3 is the fiber mat described in claim 2, The first layer is characterized by having a fourth layer disposed adjacent to the surface opposite to the surface on which the third layer is laminated, and which is composed of fibers with irregular fiber orientation.

[0014] According to this configuration, when multiple fiber mats are stacked for use, a third or fourth layer will be placed between the first and second layers. However, since the third and fourth layers are each composed of fibers with irregular fiber orientation, the fibers are more likely to become entangled between each layer, thereby improving the adhesive strength between each layer.

[0015] The invention described in claim 4 is the fiber mat described in claim 3, The third layer and the fourth layer are characterized by having the same fiber composition.

[0016] According to this configuration, when multiple fiber mats are stacked for use, a third or fourth layer is placed between the first and second layers, and since the third and fourth layers have the same fiber composition, the adhesion between the first and second layers stacked in the thickness direction can be made uniform.

[0017] In order to achieve the above object, a fiber reinforced resin material according to a fifth aspect of the present invention is characterized in that the fiber mat according to any one of the first to fourth aspects is impregnated with a curable resin composition.

[0018] According to this configuration, the short reinforcing fibers constituting the second layer overlap with the multiple short reinforcing fibers constituting the first layer in the thickness direction of the fiber reinforced resin material and act as joint materials for the multiple short reinforcing fibers in the first layer, improving the adhesion between the short reinforcing fibers in the first layer, thereby improving the strength of the short reinforcing fibers in the extension direction of the first layer in the fiber reinforced resin material. In addition, the fibers in the first and second layers are short reinforcing fibers that are aligned in one direction, so that when the curable resin composition is cured, the fibers in each layer tend to separate, allowing the fibers to fit well to the inner shape of the existing structure.

[0019] The invention described in claim 6 is the fiber reinforced resin material described in claim 5, The short reinforcing fibers of the first layer and the second layer each have a length of 10 cm to 50 cm.

[0020] According to this configuration, when the fiber-reinforced resin material is brought into close contact with an existing structure and expanded in diameter, the separation performance in which the fibers in each layer move in the longitudinal direction can be improved.

[0021] The invention described in claim 7 is the fiber reinforced resin material described in claim 5, The first layer and the second layer are characterized in that the mass ratio of the short fibers is set to 5:1 to 6:1.

[0022] According to this configuration, by setting the mass ratio of the short reinforcing fibers in the first layer to the short reinforcing fibers in the second layer to be 5:1 to 6:1, the strength in the elongation direction of the short reinforcing fibers in the first layer can be improved by approximately 10% compared to a fiber reinforced resin material that does not have a second layer, and an increase in the thickness of the fiber reinforced resin material can be suppressed.

[0023] The invention described in claim 8 is a tubular lining material used for repairing an existing pipe, The fiber reinforced resin material according to claim 5 is laminated in a thickness direction to form a tubular shape.

[0024] According to this configuration, it is possible to maintain a high separation performance of the fibers constituting the tubular lining material while ensuring a certain thickness of the tubular lining material used for repairing existing pipes such as sewer pipes. In addition, the short reinforcing fibers of the second layer act as joint materials that increase the adhesive strength between the short reinforcing fibers of the first layer, thereby improving the strength in the elongation direction of the short reinforcing fibers of the first layer in a rehabilitated pipe in which the tubular lining material is hardened. In addition, when an unhardened tubular lining material is introduced into an existing pipe and pressed against the inner surface of the existing pipe by compressed air, the short reinforcing fibers of each layer are easily separated from each other, so that good deformability in the elongation direction is ensured, and the tubular lining material can be closely attached to the inner surface of the existing pipe. This allows the tubular lining material to fit the deformed existing pipe, forming a high-quality rehabilitated pipe with fewer wrinkles.

[0025] The invention described in claim 9 is the tubular lining material described in claim 8, The tubular lining material is characterized by having a smooth thin film covering the inner peripheral surface.

[0026] According to this configuration, the inner surface of the rehabilitated pipe, which is made by hardening the tubular lining material, can be smoothly finished.

[0027] The invention described in claim 10 is the tubular lining material described in claim 8, The extension direction of the short reinforcing fibers of the first layer is inclined at an angle of 65° to 90° with respect to the axial direction of the tubular lining material.

[0028] According to this configuration, the bending strength in the extension direction of the short reinforcing fibers of the first layer is higher than the bending strength in the extension direction of the short reinforcing fibers of the second layer, and further, the extension direction of the short reinforcing fibers of the first layer is inclined at 65° to 90° with respect to the axial direction of the tubular lining material (i.e., the axial direction of the rehabilitated pipe after repair), i.e., they extend more in the circumferential direction than in the axial direction, so that the strength of the rehabilitated pipe against radial compression is high. This makes it possible to provide a structure with high strength against radial external forces that constantly act on the rehabilitated pipe. Effect of the Invention

[0029] According to the fiber mat, the fiber-reinforced resin material formed from the fiber mat, and the tubular lining material using the fiber-reinforced resin material of the present invention, the short reinforcing fibers forming the second layer act as joint materials that increase the adhesive strength of the short reinforcing fibers forming the first layer, improving the adhesiveness between the short reinforcing fibers in the first layer. This improves the strength of the short reinforcing fibers in the extension direction of the first layer in the fiber-reinforced resin material formed from the fiber mat. Furthermore, since the fibers in the first and second layers are short reinforcing fibers that are aligned in one direction, when the curable resin composition is cured, the fibers in each layer are easily separated from each other, allowing the fibers to fit well to the inner shape of the existing structure. [Brief description of the drawings]

[0030] [Figure 1] 1 is a cross-sectional view of a fiber reinforced resin material according to one embodiment of the present invention. [Diagram 2] FIG. 2 is an explanatory diagram of each fiber layer constituting the fiber mat. [Diagram 3] FIG. 2 is a diagram showing short reinforcing fibers constituting a first unidirectionally oriented layer. [Figure 4] FIG. 2 is an explanatory diagram of a step of impregnating a fiber mat with a curable resin composition. [Diagram 5] FIG. 2 is a partially cutaway perspective view showing a tubular lining material. [Figure 6] FIG. 2 is a cross-sectional view of the tubular lining material in the thickness direction. [Figure 7]1 is a schematic diagram showing a process for manufacturing a tubular lining material. [Figure 8] 3 is a schematic diagram illustrating the orientation state of short reinforcing fibers in a first short reinforcing fiber layer and short reinforcing fibers in a second short reinforcing fiber layer in a tubular lining material. FIG. [Figure 9] FIG. 1 is an explanatory diagram of a method for repairing an existing pipe using a tubular lining material. [Figure 10] FIG. 4 is a cross-sectional view showing another embodiment of a fiber reinforced resin material. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0031] 1 is a cross-sectional view of a fiber reinforced resin material 10 according to one embodiment of the present invention. The fiber reinforced resin material 10 is used for repairing or rehabilitating deteriorated existing structures, and is a material that can be made to fit the shape of the existing structure.

[0032] The fiber reinforced resin material 10 includes a base fiber layer 12, a first short reinforcing fiber layer (first layer) 14, an irregular fiber layer (third layer) 15, and a second short reinforcing fiber layer (second layer) 16. The base fiber layer 12, the first short reinforcing fiber layer 14, the irregular fiber layer 15, and the second short reinforcing fiber layer 16 are impregnated with a curable resin composition 19. Each of the fiber layers 12, 14, 15, and 16 is a layer containing fiber. In this embodiment, as shown in FIG. 2, a belt-shaped fiber mat 20 is formed by the fibers forming these layers, and then the fiber mat 20 is impregnated with the curable resin composition 19. The shape of the fiber mat 20 is not limited to a belt shape, and can be formed into any shape according to the shape of the existing structure used for repair.

[0033] Next, the fibers constituting each of the fiber layers 12, 14, 15, and 16 of the fiber reinforced resin material 10 will be described. Fig. 2 is an explanatory diagram showing a schematic diagram of the fibers constituting each of the fiber layers 12, 14, 15, and 16 in the fiber mat 20. In the following description, the layers in the fiber mat 20 corresponding to the base fiber layer 12, the first short reinforcing fiber layer 14, the irregular fiber layer 15, and the second short reinforcing fiber layer 16 are referred to as the base layer 22 (fourth layer of the fiber mat), the first unidirectionally oriented layer (first layer of the fiber mat) 24, the irregularly oriented layer 25 (third layer of the fiber mat), and the second unidirectionally oriented layer 26 (second layer of the fiber mat).

[0034] As shown in Fig. 2, the base layer 22 constituting the base fiber layer 12 is composed of fibers 22a with irregular fiber orientation. In this embodiment, a fiber strand with irregular fiber orientation is used, which is a bundle of multiple fibers (e.g., hundreds to thousands of fibers) of a predetermined length. The base layer 22 of the fiber mat 20 can be formed by placing the fibers 22a on a cloth (not shown) to form a thin veil.

[0035] The first unidirectionally oriented layer 24 constituting the first short reinforcing fiber layer 14 and the second unidirectionally oriented layer 24 constituting the second short reinforcing fiber layer 16 are each composed of a plurality of short reinforcing fibers 24a, 26a set to a predetermined length. The short reinforcing fibers 24a, 26a constituting the first and second short reinforcing fiber layers 14, 16 are each oriented in one direction, and the short reinforcing fibers 26a of the second short reinforcing fiber layer 16 are oriented so as to intersect with the short reinforcing fibers 24a of the first short reinforcing fiber layer 14 at an angle of 45° to 90°.

[0036] Next, an example of a method for forming the first and second unidirectionally oriented layers 24, 26 using short reinforcing fibers will be described. Each unidirectionally oriented layer 24, 26 can be formed by cutting a strand or roving of long reinforcing fibers, which is a bundle of a plurality of long reinforcing fibers (for example, several hundred to several thousand fibers), to a predetermined length and arranging them. For example, a strand or roving of long reinforcing fibers is cut to a predetermined length to become short reinforcing fibers, and the cut short reinforcing fibers are arranged so as to overlap in the length direction and extend in the same direction. The arranged short reinforcing fibers can be bonded together using a binder material such as an adhesive so as not to be separated. Note that when the width of the fiber mat is short (for example, 50 cm or less), the short reinforcing fibers 26a of the second unidirectionally oriented layer 26 (i.e., the short reinforcing fibers 26a extending in the width direction of the fiber mat 20) may be a strand or roving made of long reinforcing fibers cut to match the length in the width direction of the fiber mat 20. Even in such a case, the length of the reinforcing fibers is aligned with the width direction of the short fiber mat 20, so that the fiber length of the second unidirectionally oriented layer 24 can be set short. Fig. 3 is a diagram showing the short reinforcing fibers 24a constituting the first unidirectionally oriented layer 24. As shown in Fig. 3, the short reinforcing fibers 24a extend in the same direction, and are arranged so that at least a portion of them overlap with adjacent short reinforcing fibers in a direction perpendicular to the length direction. The short reinforcing fibers 26a constituting the second unidirectionally oriented layer 26 can also be arranged in the same manner as the example shown in Fig. 3.

[0037] In this embodiment, in the first unidirectionally oriented layer 24, the short reinforcing fibers 24a are arranged so as to extend parallel to the longitudinal direction of the fiber mat 20. This forms the first unidirectionally oriented layer 24 in which the short reinforcing fibers 24a extend in the longitudinal direction of the fiber mat 20. The extension direction of the short reinforcing fibers 24a is not limited to this and may be inclined with respect to the longitudinal direction of the fiber mat 20, but the short reinforcing fibers 24a are arranged so as to extend longer in the longitudinal direction than in the width direction of the fiber mat 20.

[0038] The second unidirectionally oriented layer 26 is laminated on the first unidirectionally oriented layer 24 via the irregularly oriented layer 25, and in the laminated state, the short reinforcing fibers 26a are arranged to intersect with the short reinforcing fibers 24a of the first short reinforcing fiber layer 14 at an angle of at least 45 degrees, and this intersecting angle is more preferably in the range of 85 degrees to 90 degrees. In this embodiment, in the second unidirectionally oriented layer 26, the short reinforcing fibers 26a are arranged to extend in the width direction of the fiber mat 20. This forms the second unidirectionally oriented layer 26 in which the short reinforcing fibers 26a intersect with the short reinforcing fibers 24a of the first unidirectionally oriented layer 24 at a substantially right angle. Note that the intersecting angle of the short reinforcing fibers 24a, 26a in the first and second unidirectionally oriented layers 24, 26 is not limited to 90 degrees (orthogonal) and can be set appropriately.

[0039] The irregular fiber layer 15 disposed between the first short reinforcing fiber layer 14 and the second short reinforcing fiber layer 16 is composed of fibers having irregular fiber orientation (i.e., random orientation). The fibers constituting the irregular fiber layer 15 may be short fibers or relatively long fibers, and in the case of long fibers, the fibers are preferably irregularly curved. In this embodiment, the irregular fiber layer 15 is composed of short fibers 25a that are shorter in length than the short reinforcing fibers 24a, 26a constituting the first and second short reinforcing fiber layers 14, 16 and have irregular fiber orientation. In the irregular orientation layer 25 constituting the irregular fiber layer 15, the short fibers 25a can be short fiber strands formed by bundling a plurality of short fibers.

[0040] The fiber mat 20 having the layers 22, 24, 25, and 26 can be manufactured by the following procedure. First, the fibers 22a forming the base fiber layer 12 are placed on the cloth. The short reinforcing fibers 24a forming the first short reinforcing fiber layer 14 are placed thereon. Next, the short fibers 25a constituting the irregular fiber layer 15 are scattered on the short reinforcing fibers 24a. Next, the short reinforcing fibers 26a forming the second short reinforcing fiber layer 16 are placed on the short fibers 25a. Each of the short reinforcing fibers 26a is arranged in parallel so as to intersect with the short reinforcing fibers 24a forming the first short reinforcing fiber layer 14. Note that the fiber mat 20 may be integrated by being sewn together with a thread penetrating each of the layers 22, 24, 25, and 26 as necessary. The thread used for sewing may be an elastic or non-elastic thread. The formed belt-shaped fiber mat 20 is stored in a rolled form.

[0041] In the fiber mat 20, the base fiber layer 12 is preferably a fiber layer having the same fiber structure as the irregular fiber layer 15, i.e., an irregular fiber orientation similar to that of the irregular fiber layer 15, and having approximately the same fiber length as the irregular fiber layer 15. Furthermore, the base fiber layer 12 and the irregular fiber layer 15 are preferably set so that the mass of fibers per unit area is approximately the same. In the above-mentioned procedure for manufacturing the fiber mat 20, the fibers 22a forming the base fiber layer 12 and the short fibers 25a forming the irregular fiber layer 15 are scattered to form each layer 12, 15, but the base fiber layer 12 and / or the irregular fiber layer 15 may be formed of a single fiber mat having an irregular fiber orientation, and the short reinforcing fibers 24a forming the first short reinforcing fiber layer 14 and the short reinforcing fibers 26a forming the second short reinforcing fiber layer 16 may be arranged on the fiber mat. The fiber mat constituting the base fiber layer 12 and / or the irregular fiber layer 15 may be, for example, a glass chopped strand mat (CM) in which strands cut to a specified length are dispersed in random directions, stacked to a uniform thickness, and mat-shaped with a binder, or a glass continuous strand mat (CSM) in which continuous glass fibers are stacked in a spiral shape and mat-shaped with a binder.

[0042] FIG. 4 is an explanatory diagram of a process of impregnating a fiber mat 20 with a curable resin composition 19. One end of the roll-shaped fiber mat 20 wound around a core rod 50 is pulled and wound around another rotating core rod 58. Between these two core rods 50 and 58, the band-shaped fiber mat 20 is impregnated with the curable resin composition 19. The curable resin composition 19 is stored in a tank 19 and is discharged toward the fiber mat 20 through a pipe 53 connected to the tank 19 and from a plurality of nozzle openings 54 formed at the tip of the pipe 53. On the downstream side of the nozzle openings 54, a pair of clamping plates 56-1 and 56-2 are arranged so that the cross section is wedge-shaped and narrows toward the downstream side. The fiber mat 20 passes between the clamping plates 56-1 and 56-2, whereby the fiber mat 20 is impregnated with the curable resin composition 19. Furthermore, excess curable resin composition 19 drops into container 57 installed below as it passes through clamping plates 56-1 and 56-2. This allows the fiber reinforced resin material 10 shown in FIG.

[0043] The curable resin composition 19 impregnated in the fiber mat 20 may be a resin composition that is cured by light or a resin composition that is cured by heat. Either type of curable resin composition 19 may be used in which a polymerizable resin such as a vinyl ester resin or an unsaturated polyester resin is dissolved in a solvent such as styrene. In the case of a photocurable resin composition, a photopolymerization initiator such as an azo compound is blended, and in the case of a thermosetting resin composition, an organic peroxide that reacts to heat is blended.

[0044] In the fiber reinforced resin material 10, among the fibers constituting each fiber layer 12, 14, 15, 16, at least the fibers constituting the first and second short reinforcing fiber layers 14, 16 are at least one type selected from the group consisting of glass fiber, carbon fiber, and aramid fiber. Since these fibers have high strength, the strength of the rehabilitated structure formed with the fiber reinforced resin material 10 can be sufficiently increased. In each fiber layer 12, 14, 15, 16, two or more types of the above fibers can be used in combination. Note that the fibers constituting the base fiber layer 12 and the irregular fiber layer 15 can be fibers having a lower strength than the short reinforcing fibers 24a, 26a constituting the first and second short reinforcing fiber layers 14, 16.

[0045] In the first and second short reinforcing fiber layers 14, 16, the length of the short reinforcing fibers 24a, 26a is, for example, 10 cm to 50 cm, preferably 15 cm to 40 cm, and more preferably 20 cm to 30 cm. The thickness of the fiber is not particularly limited, but may be, for example, 10 μm to 40 μm. In this embodiment, the length of the short reinforcing fibers 26a of the second short reinforcing fiber layer 16 is shorter than the length of the short reinforcing fibers 24a of the first short reinforcing fiber layer 14. The lengths of the short reinforcing fibers 24a, 26a of the first and second short reinforcing fiber layers 14, 16 may be the same, or the length of the short reinforcing fibers 24a of the first short reinforcing fiber layer 14 may be longer. When the fiber mat 20 is used as a material for a tubular lining material for repairing an existing pipe, the length of the short reinforcing fibers 24a, 26a of the first and second short reinforcing fiber layers 14, 16 is preferably less than 1 / 2 the circumference of the inner circumference of the existing pipe to be repaired, and more preferably less than 1 / 3 the circumference of the inner circumference.

[0046] The base fiber layer 12 and the irregular fiber layer 15 preferably have the same fiber structure. The fibers constituting these layers 12 and 15 can be, for example, continuous fibers stacked in a spiral shape, a plurality of roughly straight short fibers facing in an irregular direction, or randomly curved short fibers. By forming the base fiber layer 12 and the irregular fiber layer 15 from short fibers, the separation performance between the fibers can be better maintained when the fiber reinforced resin material 10 is pressed to cure the curable resin composition 19. The length of the short fibers constituting the base fiber layer 12 and the irregular fiber layer 15 is preferably shorter than the short reinforcing fibers constituting the first and second short reinforcing fiber layers 14 and 16.

[0047] In this embodiment, the mass of the short reinforcing fibers in the first short reinforcing fiber layer 14 and the second short reinforcing fiber layer 16 is larger in the first short reinforcing fiber layer 14 than in the second short reinforcing fiber layer 16. The mass ratio of the short reinforcing fibers in the first short reinforcing fiber layer 14 and the second short reinforcing fiber layer 16 is preferably in the range of 5:1 to 6:1. By setting such a mass ratio, the strength of the fiber reinforced resin material 10 in the extension direction of the short reinforcing fibers of the first short reinforcing fiber layer 14 can be increased by about 10% compared to a fiber reinforced resin material 10 that does not have the second short reinforcing fiber layer 16 and has the same mass of the short reinforcing fibers.

[0048] In this embodiment, the mass ratio of the short reinforcing fibers to the curable resin composition 19 (short reinforcing fibers:curable resin composition) is set to about 50:50 in each of the first and second short reinforcing fiber layers 14, 16. By setting such a mass ratio, the amount of the curable resin composition 19 can be reduced while the curable resin composition 19 is sufficiently permeated between the short reinforcing fibers in each of the short reinforcing fiber layers 14, 16.

[0049] In the fiber reinforced resin material 10 of this embodiment, as described above, the first short reinforcing fiber layer 14 has a larger mass of short reinforcing fibers and curable resin composition 19 than the second short reinforcing fiber layer 16. The mass of the fibers in each fiber layer 12, 14, 15, 16 is preferably set so that the first short reinforcing fiber layer 14 has the largest mass, followed by the second short reinforcing fiber layer 16, the irregular fiber layer 15, and the base fiber layer 12, in that order, and it is more preferable that the masses of the irregular fiber layer 15 and the base fiber layer 12 are set equal. As an example, the mass of the fibers in each layer is 30 g / m for the base fiber layer 12, and 30 g / m for the base fiber layer 12. 2 , the first short reinforcing fiber layer 14 is 560 g / m 2 , the irregular fiber layer 15 is 30 g / m 2 , the second short reinforcing fiber layer 16 is 100 g / m 2 It can be said that:

[0050] In addition, in the fiber reinforced resin material 10 of this embodiment, as shown in FIG. 1, the thickness d1 of the base fiber layer 12, the thickness d2 of the first short reinforcing fiber layer 14, the thickness d3 of the irregular fiber layer 15, and the thickness d4 of the second short reinforcing fiber layer 16 satisfy the relationship d2>d4>d3≧d1.

[0051] The fiber reinforced resin material 10 may have at least one of the first short reinforcing fiber layer 14 and the second short reinforcing fiber layer 16 impregnated with resin. For example, the fiber reinforced resin material 10 may not have the irregular fiber layer 15, and the first short reinforcing fiber layer 14 and the second short reinforcing fiber layer 16 may be adjacent to each other. As in the present embodiment, the irregular fiber layer 15 is provided between the first and second short reinforcing fiber layers 14, 16, so that the fibers are easily entangled between the fiber layers 14, 15, 16, and the adhesive strength between the fiber layers 14, 15, 16 is improved. The fiber reinforced resin material 10 may have two or more of the first short reinforcing fiber layer 14 and / or the second short reinforcing fiber layer 16. The order in which the first and second short reinforcing fiber layers 14, 16 are laminated is not limited to the above, and may be set arbitrarily, for example, by laminating the second short reinforcing fiber layer 16 adjacent to the base fiber layer 12.

[0052] Next, a tubular lining material 40 using the fiber reinforced resin material 10 will be described. FIG. 5 is a partially cutaway perspective view of the tubular lining material 40, and FIG. 6 is a cross-sectional view of the annular lining material 40 in the thickness direction. The tubular lining material 40 is used for repairing existing pipes such as sewer pipes, and includes, in order from the inner surface side to the outer surface side, an inner film 41, a first thin film 42, a fiber reinforced resin material 10, a second thin film 44, and an outer film 46. The tubular lining material 40 is formed in a tubular shape with a plurality of fiber reinforced resin materials 10 laminated in the thickness direction. FIG. 6 shows an example in which the tubular lining material 40 includes six layers of fiber reinforced resin materials 10-1, 10-2, 10-3, 10-4, 10-5, and 10-6, but the number of layers of the fiber reinforced resin material 10 is not limited to this and can be two or more layers.

[0053] Next, a method for manufacturing a tubular lining material 40 used for repairing an existing pipe from the fiber reinforced resin material 10 will be described. FIG.

[0054] A cylindrically shaped winding mandrel 60 is used to manufacture the tubular lining material 40. A cylindrical inner film 28 is attached in advance to the mandrel 60. The inner film 12 is used as necessary, and has the role of protecting the inner surface of the tubular lining material 40 being manufactured.

[0055] With the inner film 41 attached to the mandrel 60, the first thin film 41 formed in a strip shape is spirally wound around the outer periphery of the inner film 412. As a result, the outer periphery of the inner film 41 is covered with the cylindrical first thin film 41.

[0056] Next, the band-shaped fiber reinforced resin material 10 is spirally wound around the outer circumferential surface of the first thin film 41. As a result, the outer circumferential surface of the first thin film 41 is covered with the cylindrical fiber reinforced resin material 10. In this embodiment, two roll-shaped fiber reinforced resin materials 10-1 and 10-2 are arranged around the mandrel 60, and the fiber reinforced resin material 10 is unwound from each roll and wound around the outer circumferential surface of the first thin film 41. Then, each fiber reinforced resin material 10-1 and 10-2 is alternately wound and sequentially stacked. In the illustrated example, the two rolls of the fiber reinforced resin material 10-1 and 10-2 are arranged at positions facing each other with respect to the mandrel 60, but the number of rolls of the fiber reinforced resin material 10 may be one, or three or more rolls may be arranged around the mandrel 60. That is, the number of rolls may be one or more.

[0057] The fiber reinforced resin material 10 is wound with the angle adjusted so that the extension direction of the short reinforcing fibers constituting the above-mentioned first short reinforcing fiber layer 14 is 65 to 90° with respect to the axial direction of the tubular lining material 40.

[0058] In the present embodiment, when the extension direction of the short reinforcing fibers of the first short reinforcing fiber layer 14 is the same as the length direction of the strip-shaped fiber reinforced resin material 10, the helical angle when winding the fiber reinforced resin material 10 in a helical shape is preferably 65 to 85°. The helical angle is indicated by angle α in FIG. 8. FIG. 8(a) shows a tubular lining material 40, and FIG. 8(b) shows the orientation state of the short reinforcing fibers 24a of the first short reinforcing fiber layer 14 and the short reinforcing fibers 26a of the second short reinforcing fiber layer 16 in the tubular lining material 40. In FIG. 8(b), the straight line B forming the angle α is a straight line extending in the axial direction of the tubular lining material 40, and the straight line A is a straight line extending in the extension direction of the short reinforcing fibers 24a of the first short reinforcing fiber layer 14.

[0059] Next, the band-shaped second thin film 44 is spirally wound around the outer circumferential surface of the cylindrically-shaped fiber reinforced resin material 10. As a result, the outer circumferential surface of the fiber reinforced resin material 10 is covered with the cylindrical second thin film 44, and a tubular body 45 having layers of the first thin film 42, the fiber reinforced resin material 10, and the second thin film 44 in this order from the inner surface side is formed.

[0060] The first thin film 42 and the second thin film 44 are each a thin sheet that is smoother than the surface of the fiber reinforced resin material 10. Each thin film 42, 44 can be, for example, a nonwoven fabric made of resin such as polyester, or a nonwoven fabric slightly impregnated with resin. By covering the surface of the fiber reinforced resin material 10 with the smooth thin films 42, 44, the surface of the tubular lining material 40 can be made smooth, and the surface of the rehabilitated pipe obtained by hardening the tubular lining material 40 can be finished smoothly.

[0061] Then, outer films 46-1 and 46-2 are provided on the outer periphery of the tubular body 45. In the example shown in Fig. 7, two strip-shaped outer films 46-1 and 46-2 are arranged to face each other with the tubular body 45 in between. Then, width direction ends of the two strip-shaped outer films 46-1 and 46-2 are thermally compressed and fused to each other in a thermal compression device 62. As a result, the inner film 41 and the tubular body 45 are enclosed in the integrated outer films 46-1 and 46-2. The total width of the outer films 46-1 and 46-2 may be longer than the circumferential length of the tubular body 45.

[0062] The tubular lining material 40 thus manufactured includes, in order from the inner surface side, an inner film 41, a first thin film 42, a fiber-reinforced resin material 10, a second thin film 44, and an outer film 46, as shown in FIG. 5. The inner film 41 and the outer film 46 may be any film that has been conventionally used in the manufacture of the tubular lining material 40, and may be, for example, a polyethylene film, a polypropylene film, or a polyethylene terephthalate film. When the curable resin composition 19 is a photocurable resin composition, the inner film 41 is one that is transparent to the irradiated light. The manufactured tubular lining material 40 is crushed and folded for storage and transportation. In FIG. 7, the folded tubular lining material 40 is stored in a storage box 64.

[0063] Next, a method for repairing an existing pipe using the tubular lining material 40 will be described. FIG. 9 is an explanatory diagram of a method for repairing an existing pipe using the tubular lining material. In this embodiment, the method for repairing an existing pipe includes an introduction step of introducing the tubular lining material 40 into an existing pipe 80, an expansion step of expanding the diameter of the introduced tubular lining material 40 and pressing the tubular lining material 40 against the inner surface of the existing pipe 80 to make it adhere closely, and a hardening step of hardening the tubular lining material 40 in the expanded state. In this embodiment, a sewer pipe (sewer main pipe) buried underground is described as an example of the existing pipe 80.

[0064] The existing pipe 80 to be repaired is disposed between two manholes 82-1, 82-2, which are in communication with each other. In the repair work, water-stopping members 70-1, 70-2 for blocking the flow of sewage are installed on the existing pipes 81-1, 82-2 installed on the upstream and downstream sides of the existing pipe 80 through the manholes 82-1, 82-2. The water-stopping members 70-1, 70-2 may be rubber packers that expand when a fluid such as air is supplied to the inside of the packers.

[0065] The tubular lining material 40 is introduced into the existing pipe 80 from one manhole 82-1 (introduction process). After introduction, both ends of the tubular lining material 40 are blocked by blocking members 74-1, 74-2. In this state, compressed air is introduced into the closed space 88 of the tubular lining material 40 through a hose 77 from a compressor 76A, which is a compressed air supply means mounted on a work vehicle 76 on the ground. The compressed air introduced into the closed space 88 expands the diameter of the tubular lining material 40 and presses it against the inner peripheral surface of the existing pipe 80. As a result, the outer peripheral surface of the tubular lining material 40 comes into close contact with the inner peripheral surface of the existing pipe 80 (diameter expansion process). The air introduced from one end of the tubular lining material 40 is discharged through a hose 79 connected to the other end. The discharged air is sent to a deodorizing device 78A mounted on a work vehicle 78 arranged on the ground, and odor-causing substances are removed.

[0066] Thereafter, the light irradiation device 72 introduced into the tubular lining material 40 irradiates light from inside the tubular lining material 40. As a result, the curable resin composition 19 of the tubular lining material 40 is cured, and a resin-made rehabilitation pipe is formed inside the existing pipe 80 (curing process). The light irradiation device 72 is connected to a towing rope 73 of a towing device (not shown), and can be moved inside the tubular lining material 40 by pulling the towing rope 73. After the tubular lining material 40 is cured, the inner film 41 is peeled off as necessary. FIG. 9 shows an example of the tubular lining material 40 using a photocurable resin composition as the curable resin composition 19, but in the case of the tubular lining material 40 using a thermosetting resin composition, the tubular lining material 40 is heated by steam or the like instead of light irradiation.

[0067] In the tubular lining material 40 using the fiber reinforced resin material 10 of this embodiment, as shown in FIG. 8, each short reinforcing fiber 26a constituting the second short reinforcing fiber layer 16 overlaps with the multiple short reinforcing fibers 24a constituting the first short reinforcing fiber layer 14 in the thickness direction of the fiber reinforced resin material. As a result, the short reinforcing fibers 26a of the second short reinforcing fiber layer 16 play the role of a joint material that improves the bonding strength of the multiple short reinforcing fibers 24a of the first short reinforcing fiber layer 14, and the adhesion between the short reinforcing fibers 24a of the first short reinforcing fiber layer 14 is improved. In a fiber reinforced resin material made of short reinforcing fibers oriented in one direction, the strength in the extension direction of the fibers is reduced compared to that using long reinforcing fibers with long fiber length, but by providing the second short reinforcing fiber layer 16 as in this embodiment, the strength in the extension direction of the short reinforcing fibers 24a of the first short reinforcing fiber layer 14 can be improved.

[0068] In addition, in this embodiment, the short reinforcing fibers 26a constituting the second short reinforcing fiber layer 16 extend in a direction perpendicular to the extension direction of the short reinforcing fibers 24a of the first short reinforcing fiber layer 14, so that the number of fibers overlapping the short reinforcing fibers 26a of the second short reinforcing fiber layer 16 with the short reinforcing fibers 24a of the first layer can be increased. This can further improve the strength of the short reinforcing fibers 24a of the first short reinforcing fiber layer 14 in the extension direction. In addition, by disposing the irregular fiber layer 15 between the first short reinforcing fiber layer 14 and the second short reinforcing fiber layer 16, the adhesive strength between the layers 14, 15, and 16 is improved. Furthermore, when a tubular lining material 40 is constructed by stacking multiple fiber-reinforced resin materials 10, the base fiber layer 12 is disposed between the second short reinforcing fiber layer 16 and the first short reinforcing fiber layer 16 of another fiber-reinforced resin material 10 which is stacked thereon. However, when the base fiber layer 12 and the irregular fiber layer 15 have the same fiber structure, the adhesion between the first short reinforcing fiber layer 16 and the second short reinforcing fiber layer 16 can be made approximately uniform in the thickness direction of the tubular lining material 40.

[0069] In addition, since the first and second short reinforcing fiber layers 14, 16 are respectively composed of short reinforcing fibers 24a, 26a with lengths of 10 cm to 50 cm aligned in one direction, when the tubular lining material 40 is expanded to be attached to the existing pipe 80, the short reinforcing fibers in each layer 14, 16 are easily separated from each other, and the tubular lining material 40 can be well fitted to the inner surface shape of the existing pipe 80. In this way, the tubular lining material 40 using the fiber reinforced resin material 10 can be expanded to a large degree, so that the diameter of the tubular lining material 40 before expansion can be reduced to improve workability. In addition, when repairing an existing pipe 80 that has become uneven or deformed due to aging, the degree of expansion can be set according to the location, and a good quality rehabilitated pipe with few wrinkles that follows the shape of the unevenness or deformation can be formed.

[0070] Furthermore, in this embodiment, since the inner peripheral surface of the rehabilitating pipe formed by hardening the tubular lining material 40 is covered with the smooth first thin film 42, the inner peripheral surface of the rehabilitating pipe can be finished smoothly.

[0071] In the tubular lining material 40, the mass of the short reinforcing fibers is larger in the first short reinforcing fiber layer 14 than in the second short reinforcing fiber layer 16, and the bending strength in the extension direction of the short reinforcing fibers 24a in the first short reinforcing fiber layer 14 is higher than the bending strength in the extension direction of the short reinforcing fibers 26a in the second short reinforcing fiber layer 16. As shown in FIG. 8, the extension direction of the short reinforcing fibers 24a in the first short reinforcing fiber layer 14 is inclined at 65° to 90° with respect to the axial direction of the tubular lining material 40 (i.e., the axial direction of the rehabilitated pipe after repair) (see angle α in FIG. 8), and extends more in the circumferential direction than in the axial direction of the rehabilitated pipe, so that the strength of the rehabilitated pipe against radial compression is increased. This makes it possible to provide a structure with high strength against radial external forces that constantly act on the rehabilitated pipe.

[0072] Next, another embodiment of the fiber reinforced resin material 10 will be described. Fig. 10 is a cross-sectional view showing another embodiment of the fiber reinforced resin material 10. In the fiber reinforced resin material 10 of this embodiment, the outer surface is covered with a first coating layer 11 and a second coating layer 18, and the fiber reinforced resin material 10 includes a first thin film layer 11, a base fiber layer 12, a first short reinforcing fiber layer (first layer) 14, an irregular fiber layer (third layer) 15, a second short reinforcing fiber layer (second layer) 16, and a second thin film layer 18. The first thin film layer 11 and the second thin film layer 18 can be formed of a thin film similar to the first thin film body 42 and the second thin film body 44 described above.

[0073] The fiber reinforced resin material 10 shown in Fig. 10 can be manufactured by forming a resin-impregnated fiber mat by impregnating a fiber mat 20 with a curable resin composition 19, and then coating the outer surface of the base fiber layer 12 of this resin-impregnated fiber mat with a first thin film layer 11 and coating the outer surface of the second short reinforcing fiber layer 16 with a second thin film layer 18. In this way, the outer surface of the fiber reinforced resin material 10 is covered with the smooth thin film layers 11, 18, so that the surface of the rehabilitation structure formed by curing the fiber reinforced resin material 10 can be finished smoothly. Note that the fiber reinforced resin material 10 may have a configuration in which the thin film layer 11 or 18 is only on one surface.

[0074] The present invention is not limited to the above-described embodiments and modifications, and various changes can be made without departing from the spirit of the invention.

[0075] For example, the fiber reinforced resin material 10 of the present invention may have at least a first short reinforcing fiber layer 14 and a second short reinforcing fiber layer 16 .

[0076] Also, for example, the fiber reinforced resin material 10 may be formed by separately forming the first unidirectionally oriented layer 24, the irregularly oriented layer 25 and the second unidirectionally oriented layer 26 that constitute the fiber mat 20, impregnating each of the layers 24, 25, 26 separately with the curable resin composition 19, and then stacking the resin-impregnated layers 24, 25, 26. [Explanation of symbols]

[0077] 10 Fiber reinforced resin material 11 First coating layer 12 Base fiber layer (fourth layer) 14 First short reinforcing fiber layer (first layer) 15 Irregular fiber layer (third layer) 16 Second short reinforced fiber layer (second layer) 18 Second Coating Layer 19 Curable resin composition 20 Fiber mat 22 Base material layer 22a Textile 24 First unidirectional alignment layer 24a, 26a, 32 Reinforced fiber 25 Randomly oriented layer 25a short fiber 26 Second unidirectional alignment layer 30 Roving material 34 Binder 40 Tubular lining material 41 Inner film 42 First thin film 44 Second Thin Film 46 Outer film 72 Light irradiation device 76A Compressor 80 Sewer pipes (existing pipes) 82 Manhole

Claims

1. A first layer is formed by arranging a plurality of short reinforcing fibers of a predetermined length extending in the same direction as the fiber mat so as to extend long in the length direction of the fiber mat while overlapping the fibers in the length direction; and a second layer which is laminated on the first layer and which is formed by overlapping and arranging a plurality of short reinforcing fibers of a predetermined length extending in the same direction so as to intersect with the short reinforcing fibers of the first layer at an angle of 45° to 90° in the laminated state.

2. 2. The fiber mat according to claim 1, further comprising a third layer between the first layer and the second layer, the third layer being composed of fibers having a random fiber orientation.

3. The fiber mat according to claim 2, further comprising a fourth layer arranged adjacent to the surface of the first layer opposite to the surface on which the third layer is laminated, the fourth layer being composed of fibers having an irregular fiber orientation.

4. 4. The fiber mat according to claim 3, wherein the third layer and the fourth layer have the same fiber composition.

5. A fiber reinforced resin material comprising the fiber mat according to any one of claims 1 to 4 impregnated with a curable resin composition.

6. The fiber-reinforced resin material according to claim 5, characterized in that the short reinforcing fibers of the first layer and the second layer each have a length of 10 cm to 50 cm.

7. The fiber-reinforced resin material according to claim 5, characterized in that the mass ratio of the short reinforcing fibers between the first layer and the second layer is set to 5:1 to 6:

1.

8. A tubular lining material used for repairing existing pipes, A tubular lining material, characterized in that a plurality of the fiber-reinforced resin materials according to claim 5 are laminated in the thickness direction to form a tubular shape.

9. 9. A tubular lining material according to claim 8, further comprising a smooth thin film covering the inner circumferential surface of said tubular body.

10. The tubular lining material according to claim 8, characterized in that the extension direction of the short reinforcing fibers of the first layer is inclined at an angle of 65° to 90° with respect to the axial direction of the tubular lining material.

Images